# Conversion of qstring and number types in QT

Source: Internet
Author: User

Convert qstring to double type

Method 1. QString str= "123.45";

Double val=str.todouble (); val=123.45

Method 2: Very suitable for scientific counting method form Conversion

BOOL OK;

Double D;

D=qstring ("1234.56e-02"). ToDouble (&ok); ok=true;d;12.3456.

Convert qstring to float

1.QString str= "123.45";

float d=str.tofloat (); d=123.45

2.QString str= "R2D2";

BOOL OK;

Float d=str.tofloat (&ok); The conversion is returned by the time 0.0,ok=false;

Convert the qstring shape into plastic

1. Converting to decimal shaping

Note: The cardinality defaults to 10. When the base is 10 o'clock, and the cardinality must be 2 to 36

Room If the cardinality is 0, if the string starts with 0x, it will be converted to 16, and if it starts with a 0, it is converted to octal, otherwise it will be converted to decimal.

Qstring str= "FF";

BOOL OK;

int Dec=str.toint (&ok,10); dec=255; Ok=rue

int hex =str.toint (&ok,16); Hex=255;ok=true;

3. Normal shaping into qstring shape

Long A = 63;

QString Str=qstring::number (a,16); Str= "3f";

QString Str=qstring::number (a,16). ToUpper (); Str= "3F"; Qstring conversion char* problem!

Method one: [The net of drinking small wine]http://blog.const.net.cn/a/8642.htm
QString qstr ("Hello,word");
const char * p = qstr.tolocal8bit (). data ();
Method Two:
const char *p = qstr.tostdstring (). data ();
The conversion is constant to convert the current time to qstring ...

Public Qdatetime qdate = Qdatetime.currentdatetime ();
datetime = qdate.tostring ("yyyy mm month DD Day Ddddhh:mm:ss");
If not qtime and Qdate classes such as: How to convert a char unsigned char class received via TCP/IP to a qstring class
QString time2string (DWORD dwtime)
{
Char ctime[50] = {0};
memset (ctime,0,50);
Strftime (ctime,32, "%y-%m-%d%h:%m:%s", LocalTime (&time_t (Dwtime)));
Return QString (CTime);
} [the net of drinking wine pick]http://blog.const.net.cn/a/8642.htm

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